Selectively releasable overcenter means for slitter mechanism



R. A. BULK May 28, 1963 SELECTIVELY RELEASABLE OVERCENTER MEANS FOR SLITTER MECHANISM Filed Jan. 31, 1958 3 Sheets-Sheet 1 INVENTOR. Rose/Pr A. BULK BY W ATTORNEYS May 28, 1963 R. A. BULK 3,0 4

SELECTIVELY RELEASABLE; OVERCENTER MEANS FOR SLITTER MECHANISM Filed Jan. 51, 1958 5 Sheets-Sheet. 2

Emu fi/GZ L l g IN V EN TOR. ROBERT A 504 K Arm/vs ys May 28, 1963 R. A. BULK 3,091,146

SELECTIVELY RELEASABLE OVERCENTER MEANS FOR SLITTER MECHANISM Filed Jan. 51, 1958 3 Sheets-Sheet 5 a 52 62 6i 4 m 5 1m mil INVENTOR.

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. \"ZK wk ROBERT-BULK BY I I 1 //86 85 6 WQQWW Arr-aways United States Patent 3,091,146 SELECTIVELY RELEASABLE OVERCENTER MCEANS FER SLITTER MECHANISM Robert A. Bulk, Garfield Heights, Ohio, assignor to Harris-lntertype Corporation, Cleveland, Ghio, a corporation of Delaware Filed Jan. 31, 1958, Ser. llo. 712,419 Claims. (Cl. 83-433) The present invention relates to printing presses having a slitter for slitting material being printed by the press and in its broader aspects relates to a mechanism for slitting material carried by a rotating cylinder.

The principal object of the present invention is to provide in a machine, and particularly in a printing press, a slitting mechanism for slitting a material on a rotating cylinder of the machine wherein a circular knife for slitting the material is supported in such a manner during the slitting operation that skipping of the knife is, for all practical purposes, prevented.

Another object of the present invention is to provide a new and improved machine, and particularly a printing press, in which a circular knife for slitting material on a rotating cylinder of the machine is biased to move away from the cylinder and is positively held against movement away from the cylinder when in its slitting position.

Another object of the invention is to provide a new and improved machine, particularly a printing press, in which a mechanism is provided for slitting material carried by a rotating cylinder of the machine, the machine being so constructed and arranged that the slitting mechanism is readily accessible to the operator of the machine and so that the slitting mechanism may be easily adjusted along the length of the cylinder which carries the material to be slit.

Yet another object of the present invention is to provide a new and improved machine, particularly a printing press, in which a circular knife is movable to and from a slitting position in which it rotates about a fixed axis to slit material on a rotating cylinder, and in which the knife can be quickly removed from the slitting position by the operation of quick release means and then accurately returned to the slitting position.

A further object of the present invention is to provide a new and improved machine, particularly a printing press, as set forth in the immediately preceding object in which the slitting mechanism is adjustable along the rotating cylinder by the operation of gear means and which is preferably so constructed and arranged that the gear means can only be readily operated when the knife of the slitting mechanism is retracted from its slitting position.

A still further object of the present invention is to provide a new and improved printing press or other machine having a slitting mechanism as described in the immediately preceding object wherein the slitting mechanism has a circular knife which is releasably maintained in its slitting position by quick release means including an operating lever for actuating the quick release means which, when operated to its position in which the knife is in slitting position, is so disposed as to render the means for moving the slitting mechanism along the length of the rotating cylinder relatively inaccessible to the operator.

It is yet another object of the present invention to provide a slitting mechanism for slitting material on a rotating cylinder in which a circular knife is sup orted for movement to and from a slitting position where the periphery of the knife is in engagement with the periphery of the rotating cylinder and wherein abutment means is provided to limit the movement of the knife toward the rotating cylinder to determine its slitting position and quick release means is provided for positively holding the circular knife against the abutment means and against movement in a "ice direction away from the rotating cylinder, the quick release means including a spring effective to move the circular knife away from the slitting position when the quick release means is released.

The present invention also contemplates the provision of a new and improved printing press having a slitting mechanism and wherein the slitting mechanism has a circular knife rotatably supported by a support member which is rockable to move the knife to and from a slitting position for slitting material on a rotating cylinder, the rockable support member being supported for rocking movement by a bar-like frame member, extending along the length of the cylinder member, in a direction to move the knife toward the rotating cylinder, and wherein quick release means is connected between a body member on a second bar-like frame member extending axially of the cylinder and the rockable member and is operable to positively hold the rockable member against movement away from its slitting position, the mechanism preferably including means for moving the body member along the second bar-like member and the body member having means for effecting movement of the rockable member therewith when the body member is moved along the second bar-like member.

Further objects of the present invention will be apparent from the following detailed description of the preferred embodiment thereof made with reference to the accompanying drawings forming a part of this specification, and in which:

FIG. 1 is a fragmentary side elevational view, primarily diagrammatic, of a printing press embodying the present invention;

PEG. 2 is a plan view of the slitting mechanism of the printing press of FIG. 1 with the slitting cylinder omitted;

FIG. 3 is a front view of the mechanism shown in plan in FIG. 2;

FIG. 4 is a view taken along line 44 of FIG. 2 and showing the knife of the slitting mechanism in its slitting position;

FIG. 5 is a view corresponding to FIG. 4 but showing the knife in its retracted position; and

FIG. 6 is a fragmentary sectional view taken approximately along line 66 of FIG. 5.

The present invention is susceptible of various modifications and constructions and of use in various types of machines and applications Where it is desired to slit material carried by a rotating cylinder, but it is particularly useful when embodied in a printing press to sever sheet-like material, either individual sheets or Webs, being operated upon by the press While the sheet-like material is in engagement with a rotating cylinder and the invention is herein shown and described as embodied in a printing press in a particular manner which facilitates the operation and adjustments of the slitting mechanism by the operator of the press.

Referring to the drawings, FIG. 1 shows a printing press having an image-carrying cylinder 10 which, as shown, is a blanket cylinder of a lithographic press, an impression cylinder 11 and a transfer cylinder 12 supported between side frames 13 of the press, only one of which is shown. It is to be understood that, in addition to the above, the press shown in the drawings includes a plate cylinder, which cooperates with the blanket cylinder, and inking and dampening means for the plate cylinder. The press may also include conventional means for feeding sheets to the impression cylinder.

The arrangement of the blanket cylinder, impression cylinder and transfer cylinder is a conventional arrangement and sheets to be printed are fed to the impression cylinder and carried thereby to the nip of the blanket cylinder and impression cylinder and are printed as they pass between the cylinders. The sheets are transferred from the impression cylinder to the transfer cylinder 12 and then to a slitting cylinder 15. From the slitting cylinder 15, the sheets are passed to a delivery cylinder 16 and a cooperating chain delivery effective to deliver the sheets from the press to a delivery pile. The delivery 'cylinderand the slitting cylinder are journalled between the side frames of the press adjacent the exit side thereof with the slitting cylinder disposed between the delivery cylinder and the transfer cylinder 12. The delivery cylindery'the slitting cylinder, and the transfer cylinder are arranged generally in a horizontal row While the impres sion cylinder is disposed above the transfer cylinder and the blanket cylinder is disposed above the impression cylinder.

Each of the above-mentioned cylinders 11, 12 and 15 is provided with conventional sheet-gripping means for gripping the leading edge of the sheet as it is transferred to the cylinder and for clamping the leading edge against the cylinder to cause the sheet to rotate with the cylinder.

The sheet-gripping means for the slitting cylinder is shown in FIG. 4. The sheet-gripping means will not be described, and is not shown, in detail since the construction and manner of operation of sheet-gripping means for cylinders are well known to those skilled in the art. Suffice it to say that the sheet-gripping means comprises a plurality of cam-operated gripper fingers 18 which are carried over the top of the cylinder and is transferred to the delivery cylinder when the fingers are moving downwardly on the opposite side of the slitting cylinder from the transfer cylinder.

A slitting mechanism 22 is disposed above the slitting cylinder 15 and includes a circular knife 23 which is adapted to engage the periphery of the cylinder 15 or a slitting band thereon and to slit the sheet of material carried thereby lengthwise into two sections. The circular knife 23 is journally supported in a boss 24 for rotation about an axis parallel to the axis of cylinder 15. The boss 24 is part of a rockable support member 25 having spaced portions providing spaced arms 26, 27 extending radially outwardly from the boss 24. The arms 26, 27 have aligned bores 28 therein which receive a bar 30 extending between the side frames 13 of the press above the slitting cylinder 15 and mount the support slitting position where the periphery of the knife is in engagement with the periphery of, or the band on the slitting cylinder. In the illustrated embodiment the knife engages a band 31 secured to the cylinder 'by a conventional clamp 32 located in the gap 20 of the slitting cylinder.

The movement of the circular knife 23 toward the slitting cylinder 15 is limited by a stop member 32 carried by a body member 33 mounted on a bar 34 extending between the side frames 13 of the press above and parallel to the bar 30. The body member 33 has a close-fitting bore 35 through which the bar 34 passes and a depending portion 36 which extends downwardly from the main body member 33 and which has a close-fitting bore 37 in which the bar 30 is received. The depending portion 36 is' disposed between the arms 26, 27 of the support member 25 and the width of the portion 36 is such as to closely fit the space between the arms 26, 27

but is also such as to permit the support member 25 to rock on the bar 30 relative to the depending portion 36.

The stop member 32 for limiting the movement of the support member '25 is carried by the body member'33 and is in the form of a threaded screw which is threaded through a wall 38 of the body member 33 and is disposed above the bar 30 in position to be engaged by an The limit position of the knife can be adjusted by thread-.

ing the threaded member 32 so that it moves axially relative to the body member 33. The threaded member 32 is preferably provided with a lock nut 41 to lock the member 32 in its desired position. As the slitting mechanism is viewed in FIGS. 4 and 5, the arm 40 extends, upwardly from the arm 27 of the support member 25 along the right-hand side of the body member 33.

The support member 25 includes a pair of spaced posts 42 which extend upwardly from the support member 25 along the left-hand side of the body member 33 as it is viewed in FIGS. 4 and 5. At their upper ends the posts 42 support an eccentric member or crank 43 for moving the circular knife 23 to its slitting position and for holding the knife against movement away from the cylinder while in the slitting position so that the knife rotates about a fixed axis during the slitting operation. The eccentric member 43 is preferably machined as a single piece comprising spaced journal portions 44 rotatable in bores 45 in the posts 42, and an off-center portion or pin 46 extending between the 'journal portions 44.

The pin 46 engages an abutment member. 50 having a threaded portion 52 and a head 51, the latter being disposed between the journal portions 44. The abutment member 50 is supported by the body member 33 with the threaded portion 52 lying along a horizontal line through the axis of rotation of the eccentric member 43 and with the head 51 disposed between the posts 42 in position to be engaged by the pin 46-.

The support member 25 is biased in a clockwise direction about the bar 30, as the suport member is'viewed in FIGS. 4 and 5, by a spring 55 connected between a lug 56 on the body member 33 and a bar portion 57 joining the arms 26, 27 at their ends remote from the knife 23. The spring 55 urges the knife away from the cylinder 15 and the pin 46 of the eccentric member 43 into engagement with the head 51 of-the abutment member 50. The spring and the eccentric member 43 will cooperate to urge the slitting knife to an inactive or retracted position where the pin 46 is disposed substantially along the extended axis of the abutment member 50 and Where, in effect, the low point of the eccentric member engages the abutment member 50. When the accentric member 43 is rotated from the described position, the knife 23 and the support member 25 are moved counterclockwise about the bar 30, as the slitting mechanism is viewed in FIGS. 4 and 5, until the high point of the eccentric member moves through the point of engagement of the eccentric member with the abutment member 50.

An operating lever is carried by an enlarged part 58a of the journal portion 44 rotatably supported in the lefthaud one of the posts 42 as the slitting mechanism is viewed in FIG. 2. The operating lever 58 extends generally perpendicularly to the axis of the eccentric member 43 and when the low point of the eccentric member is in engagement with the abutment member 50 the cir cular knife 23 is in a retracted position and the lever 58 depends downwardly along the adjacent post 42. The spring 55 urges the eccentric member to a position where its low point is in engagement with the abutment member and the knife retracted, except when thehigh point of V the member is on center Where it is in engagement with the abutment member. When the high point is on one side of center the eccentric member will be moved counterclockwise by the spring until its low point engages the eccentric moves over center and the lever engages a pin 60 supported by one of the posts 42 above the eccentric member 43. When the lever 58 is in engagement with the pin 60 the hi h point of the eccentric member s3 is just over center, i.e., the high point of the eccentric member 43 has passed through the point of engagement of the eccentric member with the abutment member. Since the eccentric member has moved over center and the pin 69 prevents the lever 58 from rotating clockwise which is the direction in which it is now urged by the spring 55, the circular knife 23 is held in a slitting position adjacent the cylinder 15 and is positively prevented by the eccentric member 43 and the abutment member from moving away from the cylinder 15. It will be noted that the spring 55 prevents movement of the knife and support member 25 toward the cylinder as well as holding the eccentric member 43 in engagement with the abutment member 50. When the lever 58 is moved counterclockwise from its upwardly extending position shown in FIG. 2 the pin 46 of the eccentric member is moved over center and the spring 55 operates to efiect rotation of the eccentric member until the low point engages the abutment member 59 and, in turn, to effect a fast retraction of the knife from its position. The eccentric member 4-3 and the spring 55 cooperate with the abutment member 5% to provide an over center, toggle-like quick release means for holding the circular knife 23 in a position adjacent the cylinder and for quickly moving it to a retracted position.

The abutment member 59 threads into a knurled nut 62 positioned in a cutout 63 in the body member 33. Rotation of the nut 62. will thread the abutment member 50 axially to adjust the position of the head 51 engaged by the pin 46 and to adjust the slitting position of the knife to a position where the knife is in engagement with the band 3-1 without substantial pressure therebetween. If the abutment member is moved toward the eccentric member the knife will move toward slitting cylinder 15. The nut 62 carries a detent receiving portion 64- which rotates with the nut and which has a plurality of grooves 65 therein adapted to receive a detent 66 supported in a bore 67 in the body member and biased to engage with the detent portion 64 by a spring 68 in the bore. Each groove preferably represents an adjustment of .001 inch. Rotation of the nut 62 will cam the detent 66 out of the particular groove in which it is positioned but in absence of a direct force tending to rotate the nut 62 the detent 66 will hold the nut 62 in its adjusted position.

It can now be seen that, in the illustrated embodiment, the spring 55 continuously urges the support member 25 and the knife 23 away from the slitting cylinder 15 toward a retracted position Where the low point of the eccentric member is in engagement with the abutment member 56, and that the knife is moved to its slitting position by moving the eccentric member over center to a self-locking position where the high point of the eccentric member is just over center. The eccentric member and eccentric may be considered as forming a toggle-like linkage movable through center and having a greater degree of movement on one side of center than on the other or as coop erating cam elements movable to a self-locking position for holding the knife in its slitting position against the action of the spring 55.

The stop member 32 is preferably adjusted to a position where it is not engaged by the arm 46 when the knife is riding on the band 31, but where it will be engaged if the knife is moved to a point where it would ride on the cylinder itself rather than on the band. Once the stop member 32 is set in this position, the knife cannot be moved to a position in engagement with the periphery of the slitting cylinder itself. Since the band 31 is conventionally about .020 inch thick, there will preferably be about .015 inch of clearance between the stop member 32 and the arm 46 when the knife is in slitting position. In some cases it may be desirable for the knife to ride directly on the cylinder periphery and in this case the stop member 32 may be set to engage the arm 49 when the knife is in slitting position.

If desired the stop member 32 can be adjusted so that the arm 4%} engages the stop member 32 when the knife is in its slitting position and when the knife rides on the band 31. in this case the knife is positively held against movement in either direction during the slitting operation and the action of spring 55 is not required to prevent movement of the knife toward [the cylinder when the knife is in its slitting position.

According to another aspect of the present invention the slitting mechanism is adjustable axially along the periphery of \the slitting cylinder 15 by the operation of gear means. in the disclosed embodiment the bar 34 has an axially extending rack 5% on one side thereof and the body member 33 is provided with a cut-out portion in which a pinion 71 is disposed and which meshes with the rack. The pinion 71 is fixed to the lower end of a vertical shaft 73 rotatably supported by the body member 33 and extending upwardly therefrom. Fixed .to the upper end of the shaft 73 is a handwheel '74 which may be rotated to rotate the shaft 73 and pinion 71 to move the body member 33 and the support member 25 along the bars 30, 3d. The suppont member 25 will move along the bars with the body member 33 since the depending portion 36 of the body member is disposed to closely fit between the arms 26, 27 of the support member 25.

When the slitting mechanism has been adjusted axially of the slitting cylinder it may be locked in its adjusted position by the operation of means for preventing movement of the body member 33 along the bars 30, 34. As is shown in FXGS. 4 and 5, the depending portion 36 is formed to provide a boss 73 disposed between the arms 26, 27 of the support member 25. The boss 78 has a bore 86 therein which receives a locking sleeve 81 having a central axial bore 32 for receiving a screw member 83 having a hexagonal head extending upwardly between the arms 26, 27, a collar which engages the upper end of the sleeve 81, and a threaded portion disposed adjacent the bar 35 and adapted to cooperate with a nut 36 in the bore 8%. The member 33 may be rotated to thread it into and out of the lock nut 86. The bore 8t) of the boss 78 intersects the bore 28 in which the bar 30 is received and the sleeve 81 and nut 86 are each provided with a fiat adapted to clamp against the bar 34} when the screw member is tightened. The head 84 of the member 83 is adapted to be used to rotate the threaded member in one direction to draw the collar 81 and the nut 85 against the bar 30* and in the other direction to release the clamping pressure on the bar 31 by the nut 86 and the sleeve 81. When the nut 86 and locking sleeve 81 are drawn together to clamp the bar 30, the slitting mechanism is locked against movement along the bars.

The body member 33 is also provided with a pair of bosses 9h, 91 which have bores therein that intersect the bore 35 which receives the bar 34 Each of the bores in the bosses 9h, 91 has disposed therein a nut 92 and a locking sleeve 93 which cooperate in the same manner as the nut 85 and the sleeve 81 to lock the body member against movement relative to the bar 34 when a bolt 94 received in each sleeve and threaded into the respective nut is rotated to tighten the sleeve and the nut on the bar 34. Since the construction and the operation of the sleeves 93 and nut 92 for locking the body member 33 against movement relative to the bar 34 are the same as that for locking it against movement relative to the bar 3%, the description will not be repeated.

It can now be seen that the present invention provides a slitting mechanism wherein a circular slitting knife for slitting material on a rotating cylinder is movable into a slitting position and positively held against movement away from the cylinder while in the position and wherein the knife may be quickly retracted from its slitting position and accurately returned thereto, the mechanism being supported for ready adjustment along the axial periphery of the slitting cylinder.

Another feature of the present invention is that the press is so constructed and arranged that the operator has ready access to the slitting mechanism. As is shown in FIG. 1, the press is provided 'with a cross platform 95 immediately above the slitting cylinder 15 and adjacent to the bars 30, 34. An operator on the cross platform may readily reach the handwheel 74 for adjusting the slitting mechanism along the cylinder and the lever 53 for moving the circular slitting knife between its slitting and retracted positions. In the arrangement shown in FIG. 1, the lever 58 when extending upwardly as when the knife is in its slitting position is intermediate the opera-tor on the cross platform and the hand-wheel 54 and if the operator were to attempt to move the slitting mechanism along the bars 30, 34 with the slitting wheel in its slitting position, the lever 58 would make access to the handwheel 54 inconvenient and let the openator know that the circular knife had not been retracted.

The disclosed slitting mechanism may be readily and accurately adjusted to any position along the bars 30, 34 and the knife readily actuated to its slitting position where the arm 40 is in engagement with the stop member 32 and the periphery of the knife is in engagement with the surface of the rotating cylinder or the band thereon to slit material. It will be noted that operation of the quickrelease means to Withdraw the knife 23 from its slitting position does not destroy the setting of the slitting knife and when the eccentric crank 43 is again operated to move the slitting knife to its slitting position, the knife will be returned to its adjusted position. This enables adjustments to be readily made and maintained While the mechanism is adjusted axially of'the cylinder. When a band is used as in the disclosed embodiment, the band clamp is also supported for adjustment along the cylinder.

As is shown in FIGS. 4 and 5, the depending portion 36 preferably carries a shield 99 which extends forwardly alongside of the knife 23.

In sheet printing presses, the cylinders have gaps, as described herein, in which the sheet gripper fingers are disposed. When the disclosed slitting device is used on a sheet press, the knife 23 will not bounce at the gaps and will not skip. a

While the preferred embodiment of the present invention has been described in considerable detail, it is my intention to cover hereby all constructions, modifications and arrangements which fall within the scope and spirit 'of the present invention, and it is to be understood that when the appended claims refer to the slitting knife as engaging the periphery of the cylinder that this is intended to cover both a knife which engages the periphery of the cylinder proper and a knife which engages a band or other member carried by the rotating cylinder.

Having thus described my invention, what I claim is:

l. Ina mechanism comprising a rotating cylinder having an axially extending gap in the periphery thereof and carrying sheet-like material, a device for slitting said sheet-like material, said device comprising a circular slitting knife adjacent said cylinder and having a slitting position with'the periphery thereof substantially in en- 7 gagement with said cylinder and where said gap periodically passes under said knife upon rotation of said cylinder, support means supporting said knife for rotation about an axis stationary with respect to said support means, means mounting said support means for movement in a first direction to move said knife toward said cylinder and toward said slitting position and for movement in a second direction to move said knife from said position and in a direction away from said rotating cylinder, stationary stop means adjacent said support means and engaged by a part on said support means when said knife is in said slitting position to limit said support means and knife against movement in said first direction, and means for selectively actuating said support means in its said first and second directions including releasable over-center means operatively connected to said support means for selectively and positively holding said part against said stop means thereby preventing movement of said support means and part away from said stop means in said second direction.

2. In a mechanism comprising a rotating cylinder having an axially extending gap therein and carrying sheetlike material, a circular slitting knife adjacent said cylinder and having a slitting position with the periphery thereof substantially in engagement with said cylinder and where said gap periodically passes under said knife upon rotation of said cylinder, a movable support member supporting said knife for rotation about an axis fixed with respect to the support member, support means mounting said support member for movement in a first direction to move said knife toward said cylinder and toward said slitting position and for movement in a second direction to move said knife from said position and in a direction away fromv said rotating cylinder, releasable actuating means for selectively moving said support member and knife into slitting position, and biasing means urging said support member in said second direction and effective upon the release of said releasable means to move said knife from said slitting position, said actuating means comprising a first member mounted on said support means, a second member mounted on said knife support member engageable with said first member and coopera-ble therewith upon relative movement therebetween in a first direction to efiect'movement of said knife into slitting position, means for moving one of said first and second members relative to the other from a first relative position to a sec ond relative position to actuate movement of said knife into said slitting position, and means for holding said first and second members in said second-relative position in' cluding cam surfaces effective to releasably hold said first and second members against movement in a second direction opposite said first direction and for holding said knife against movement out of slitting position.

3. A slitting device comprising a slitting knife having a slitting position, a movable support member supporting said knife, means mounting said support member for movement in a first direction to move said knife to said slitting position and for movement in a second direction to move said knife from said position, a stationary member adjacent said support member, cooperating self-locking cam elements on said support member and said stationary member respectively and comprising an eccentric member and an abutment member engaged by said eccentric member and said eccentric member having a high point movable from one side of the point of engagement of said eccentric member and abutment member upon rotation of said eccentric member in one direction through the point of engagement to move said support member and knife into slitting position, and means preventing continued movement of said eccentric member .after the high point passes through the point of engagement from said one side, and spring means urging said support member in said second direction.

4. In a slitting device for slitting material on a' rotating cylinder, a body member supported adjacent said cylinder, a knife support member, means mounting said knife support member adjacent said body member for oscillatory movement relative thereto, a circular rotatable slitting knife carried by'said knife support member and moved toward and away from a slitting position on osbody member and said support member and actuatable to move and hold said support member against said stop means to hold said knife into slitting position.

5. In a device as defined in claim 4 wherein said actuating means comprises a first member mounted on said body member, a second member mounted on said support member engageable with said first member and cooperable upon relative movement therebetween in a first direction to effect movement of said knife into slitting position, means for moving one of said first and second members relative to the other from a first relative position to a second relative position to actuate movement of said knife into said slitting position, and means for holding said first and second members in said second relative position including cam surfaces effective to releasably hold the members against movement in a second direction opposite said first direction and for holding said knife against movement out of said slitting position.

6. In a slitting device as defined in claim 4 wherein said actuating means comprises cooperating cam elements on said body member and said support member respectively, one of said cam elements being an eccentric member and the other of said elements being an abutment member engaged by said eccentric member and said eccentric member having a high point movable from one side of the point of engagement of said eccentric member and abutment member upon rotation of the said eccentric member in one direction through the point of engagement to move said support member and knife into slitting position, and means preventing continued movement of said eccentric member after passing through said point of engagement in said one direction and while said knife is in slitting position.

7. A slitting device comprising a body member, a knife support member, means mounting said knife support member for oscillatory movement relative to said body member, a slitting knife carried by said knife support member and moved to and from slitting position on oscillation of said knife support member, adiustable stop means engaged by said knife support member to stop its movement in a direction toward said slitting position to determine the latter, a spring connected to said support member and urging said knife support member away from said stop means, and over-center mechanism carried by said members and movable from one side of center to the other to actuate said knife support member toward said stop means and including an adjustable abutment carried by one of said members and engageable to limit the movement to said other side of center and adjustable to determine the throw of said mechanism.

8. In a mechanism comprising a rotating cylinder having an axially extending gap in the periphery thereof and carrying sheet-like material, a device for slitting said sheet-like material, said device comprising a circular slitting knife adjacent said cylinder and having a slitting position with the periphery thereof substantially in engagement with said cylinder and Where said gap periodically passes under said knife upon rotation of said cylinder, support means supporting said knife for rotation about an axis stationary with respect to said support means, means mounting said support means for movement in a first direction to move said knife toward said cylinder and toward said slitting position and for movement in a second direction to move said knife from said position and in a direction away from said rotating cylinder, stationary stop means adjacent said support means and engaged by a part on said support means when said knife is in said slitting position to limit said support means and knife against movement in said first direction, and means for selectively actuating said support means in its said first and second directions inciuding releasable overcenter means operatively connected to said support means for selectively and positively holding said part against said stop means, thereby preventing movement of said support means and part away from said stop means in said second direction, said overcenter means including means for adjusting the effective length of said overcenter means when in overcenter position, and spring means acting to urge said support means from said slitting position upon release of said overcenter center means.

9. In a slitting mechanism for slitting sheet material on a rotatable cylinder having a gap therein, a knife support member rotatably supporting a circular knife, means supporting said member for movement to and from a slitting position where said knife is substantially in engagement with said cylinder and where said gap periodically passes under said knife upon rotation of said cylinder, an overcenter mechanism connected to said support member and actuatable to move said member to and from slitting position, an abutment adjacent said knife support member, said overcenter mechanism being on one side of center and engaging said abutment when said member is in slitting position, a spring active on said member to urge it away from said cylinder and urging said overcenter mechanism into engagement with said abutment when the mechanism is on said one side of center to maintain said member in slitting position, said spring being effective to move said support member from said slitting position when said overcenter means is moved to the other side of center from said one side of center.

10. In a mechanism comprising a rotating cylinder having an axially extending gap in the periphery thereof and sheet-like material thereon, a slitting device for slitting said sheet-like material, said device comprising a knife support member, means supporting said member for movement in a first direction toward and in a second direction away from said cylinder, a circular knife supported by said member for rotation about an axis fixed with respect to said member and moved from a retracted position to a slitting position wherein said gap passes under said knife upon movement of said member in said first direction to a predetermined position, overcenter means for actuating said member in said first and second directions and movable in one direction through center as said member moves to said predetermined position, abutment means engaged by said overcenter actuating means to limit its movement in said one direction after moving through center, and biasing means operatively connected to said member and urging the latter in said second direction.

References Cited in the file of this patent UNITED STATES PATENTS 263,983 Spooner Sept. 5, 1882 958,455 Worcester May 17, 1910 1,065,882 Lockwood June 24, 1913 1,618,191 Hemberger Feb. 22, 1927 2,000,175 Johnstone et a1. May 7, 1935 2,003,404 Valentine June 4, 1935 2,228,442 Coleman Jan. 14, 1941 2,542,867 Harrold Feb. 20, 1951 2,684,117 Wood July 20, 1954 2,702,002 Koch Feb. 15, 1955 2,767,790 Jacobsen et al. Oct. 23, 1956 FOREIGN PATENTS 466,838 Germany Oct. 13, 1928 501,338 Germany July 2, 1930 

1. IN A MECHANISM COMPRISING A ROTATING CYLINDER HAVING AN AXIALLY EXTENDING GAP IN THE PERIPHERY THEREOF AND CARRYING SHEET-LIKE MATERIAL, A DEVICE FOR SLITTING SAID SHEET-LIKE MATERIAL, SAID DEVICE COMPRISING A CIRCULAR SLITTING KNIFE ADJACENT SAID CYLINDER AND HAVING A SLITTING POSITION WITH THE PERIPHERY THEREOF SUBSTANTIALLY IN ENGAGEMENT WITH SAID CYLINDER AND WHERE SAID GAP PERIODICALLY PASSES UNDER SAID KNIFE UPON ROTATION OF SAID CYLINDER, SUPPORT MEANS SUPPORTING SAID KNIFE FOR ROTATION ABOUT AN AXIS STATIONARY WITH RESPECT TO SAID SUPPORT MEANS, MEANS MOUNTING SAID SUPPORT MEANS FOR MOVEMENT IN A FIRST DIRECTION TO MOVE SAID KNIFE TOWARD SAID CYLINDER AND TOWARD SAID SLITTING POSITION AND FOR MOVEMENT IN A SECOND DIRECTION TO MOVE SAID KNIFE FROM SAID POSITION AND IN A DIRECTION AWAY FROM SAID ROTATING CYLINDER, STATIONARY STOP MEANS ADJACENT SAID SUPPORT MEANS AND ENGAGED BY A PART ON SAID SUPPORT MEANS WHEN SAID KNIFE IS IN SAID SLITTING POSITION TO LIMIT SAID SUPPORT MEANS AND KNIFE AGAINST MOVEMENT IN SAID FIRST DIRECTION, AND MEANS FOR SELECTIVELY ACTUATING SAID SUPPORT MEANS IN ITS SAID FIRST AND SECOND DIRECTIONS INCLUDING RELEASEABLE OVER-CENTER MEANS OPERATIVELY CONNECTED TO SAID SUPPORT MEANS FOR SELECTIVELY AND POSITIVELY HOLDING SAID PART AGAINST SAID STOP MEANS THEREBY PREVENTING MOVEMENT OF SAID SUPPORT MEANS AND PART AWAY FROM SAID STOP MEANS IN SAID SECOND DIRECTION 